The present invention relates to connector modules, e.g., RJ-45 connector modules, and more particulary to connector modules that incorporate as an integral part thereof removable and/or repairable magnetic filtering, light emitting diode (LED) indicators, and isolation and protective components that enhance transceiver performance and reject common mode noise. Advantageously, the connector modules of the present invention utilize commonly-available RJ-45 connectors, are small and compact, have a footprint size that is no larger than or reduced from that which has heretofore been available for such modules, and facilitate repair and/or replacement (e.g., upgrades).
Modern communication and transmission systems, such as are commonly used in a Local Area Network (LAN), transfer vast amounts of digital data at increasingly faster rates over Unshielded Twisted Pair (UTP) copper cable or other suitable cables (e.g., fiber optic). The signal path for LAN devices is generally initiated by a silicon-based driver integrated circuit (IC). The signal generated by the IC driver passes through passive filtering devices to limit the frequency passband, and then through some isolation transformers, and then out of a connector onto a UTP cable. The connector of choice for many LAN applications used to interface with UTP cable (or other transmission cable) is referred to as an RJ-45 connector.
In recent years, a wide variety of RJ-45 connector modules have been employed to facilitate the connection between the IC driver, located on a printed circuit board (PCB) as part of some communication device or processor, and the UTP cabling, which cabling interconnects the various devices that form the LAN.
U.S. Pat. Nos. 4,695,115; 4,772,224; 5,015,204; 5,069,641; 5,139,442; and 5,397,250 are representative of the RJ-45, and similar (e.g., RJ-11), connector modules that have been used in the past for LAN and telephonic connections. As shown in these prior art patents, a module is provided for mounting on a PCB. The module includes a plug-receiving opening into which the desired jack, usually an RJ-11 or RJ-45 type jack, may be detachably inserted. The module has conductors included as an integral part thereof that connect each wire or pin of the RJ-11 or RJ-45 connector to a suitable pin or leg of the module. The pins or legs of the module are attached, e.g., soldered, to the PCB in conventional manner. Once mounted on a circuit board, the module thus provides a simple and easy way to connect and disconnect the RJ-11 or RJ-45 jack, which is usually connected to UTP or other multi-conductor cabling system, to electrical circuitry contained on the PCB.
In order to filter out noise and extraneous signals that may be present on or induced in the signals that pass through the connector modules, and in order to prevent extraneous ElectroMagnetic Interference (EMI) from being coupled into the signal lines that pass through the conductor, it is known in the art to employ filtering and EMI protection circuitry adjacent the connector module. Such filtering and/or EMI protection circuitry traditionally places discrete filtering components on the printed circuit board near the connector module.
Placing discrete filtering components on the printed circuit board near the connector module not only consumes valuable space, but also sacrifices performance and adds unnecessary complexity to the design and number of components that must be used to realize the circuitry. What is needed, therefore, is a connector module which incorporates the desired filtering and protection circuitry within the connector module itself, and which thereby frees up additional board space for other needed circuit componentry, and/or allows the overall circuit board size to be smaller.
Some of the connector modules known in the art do attempt to incorporate protection, isolation and/or filtering circuitry within the module housing itself. However, such modules tend to be larger (have a larger "footprint") than do modules without such circuitry, and/or the amount of filtering, isolation and protection provided by such "built-in" components lacks sufficient capability to adequately perform the needed protective, isolation and filtering functions. Further, connector modules modified to include such isolation and/or filtering circuitry typically require extensive tooling changes that are expensive and difficult to realize. What is thus needed is a connector module that has built-in or integral isolation, filtering and protective circuitry and which offers the needed isolation/protection/filtering performance sophistication demanded by today's high speed LAN or other signal transmission and communication protocols, yet does not increase, and may even reduce, the PCB footprint required for such module. In addition, it is important that such connector module be fully compatible with existing connectors.
It is also known in the art to employ light emitting diodes (LEDs) in conjunction with an RJ-45 connector module to provide a visual indication that data is being transmitted through the cable connected to the connector to or from circuitry located on (or coupled to) the PCB on which the connector module is mounted. Such LEDs are typically used in pairs, with one LED indicating whether data is being received through the RJ-45 connector module (from a source remote from the PCB), and the other LED indicating whether data is being transmitted out through the RJ-45 connector module. Sometimes different colors, e.g., red, green or yellow, may to use to signify different events or non-events relative to the data trasnfer. For example, the color red may be used to visually indicate that no data is being received or transmitted through the connector module, while the color green may be used to visually indicate that data is being received or transmitted through the connector module. Unfortunately, the use of such LEDs within a connector module creates its own set of problems. Not only might the footprint size of the module increase when LEDs are used, but the electrical current flowing through the wires that drive the LEDs may itself be a source of electrical noise that is coupled into the signal lines passing through the connector module. Hence, it is evident that what is needed is a connector module having LED indicators as an integral part thereof, but wherein the use of such LED indicators does not increase the footprint size, and does not function as a source of electrical noise.